A variable-pitch propeller of this kind for a ship is known from U.S. Pat. No. 3,853,427. The adjusting element used for it has a number of straight grooves running perpendicular to the direction of sliding of the adjusting element. When said adjusting element is slid, the propeller blades can be adjusted between a forward driving position, a neutral position in which the propeller blades produce no driving force, and a reverse driving position.
Although the propeller blades of this known propeller can be rotated through a considerable angle, it is not possible to move them into such a position that the blades produce a minimum resistance when the vessel is being propelled in another way. This occurs, for example, in the case of a sailing vessel which is propelled by the wind in such a way that the propeller can be put out of operation.
If, therefore, this known propeller is being used as an auxiliary drive for, for example, a sailing vessel, said propeller will have to be taken out of the water, in order to minimise the resistance during sail operation alone. Where there is an outboard motor, it is possible to do this, but once a fixed internal engine with a fixed propeller shaft is used this is no longer possible.